Until recently, I had never given much thought to crow poop. That might have been a mistake.

Fortunately, Julie Ellis, an infectious disease professor at Tufts University, is doing the thinking for me.

She has been collecting and analyzing crow poop in Massachusetts for a while. In the process, Ellis and colleagues have discovered something alarming, maybe even very alarming: Antibiotic-resistant bacteria in the feces of crows, in the Bay State and three other states.

“We’ve documented human-derived drug resistance where it shouldn’t be – in wildlife and the environment,” Ellis told Environmental Health News.

This is bad, and we have only ourselves to blame. We are using antibiotics stupidly, making it easier for resistant bacteria to evolve, and refuse to wise up because it would be a little bit expensive and difficult.

“Crow poop” is a funny phrase, which is why I’m using it, but this really isn’t a funny topic.

Shockingly, about 80 percent of antibiotics used in the U.S. are fed routinely to livestock, not because they’re sick but just to speed up their growth a bit. We’re endangering our own lives to save a few cents on our processed chicken wings and hamburger.

Even the antibiotics prescribed to people in the United States are often wasted, says the Centers for Disease Control and Prevention. It estimates that half of such prescriptions are unnecessary. They’re a stopgap, a fallback, for both doctors and for patients: I feel sick, doc, give me an antibiotic!

This is, as I said, stupid, and we’re paying the price already – 23,000 unnecessary deaths each year in the U.S., says the CDC.

This latest study hints that the price could get a lot higher. So far, drug-resistance in the U.S. is mostly a problem in hospitals and a few other locations where lots of sick people stay close together, swapping bacteria and speeding up their evolution.

If such strains are starting to exist in the wild, however, we’ll all the vulnerable.

Ellis is careful to point out that her work didn’t mean killer bacteria are loose in our midst. This isn’t “a smoking gun,” she told Scientific American. But it’s still worrisome.

And although New Hampshire wasn’t one of the states where Ellis and her team found the problem, crows are far-flying creatures. Plenty of them have crossed north over the state border with who knows what lurking in their guts, and may well have pooped some of it onto my yard while raiding the apple trees.

Elizabeth Daly, chief of the Infectious Disease Surveillance Section of New Hampshire Department of Health, put it this way in an email response to my query: “Although the implication to human health is not clear, this reminder of widespread emergence of drug resistance is further evidence we must be good stewards of available antibiotics, including rational use in human and veterinary medicine and catalyze the development of new drugs.”

Many of us have heard of MRSA, a bacteria resistant to common antibiotics that is causing a wave of infections that are hard to treat, but there are plenty of other diseases cropping up that don’t succumb to antibiotics the way they used to.

The problem is so widespread that some medical officials are warning of a possible “post-antibiotic era,” in which routine infections become life-threatening and we’re all vulnerable to diseases in a way Americans haven’t had to face since horse-and-buggy days.

The Centers for Disease Control issued a report this year titled “Antibiotic Resistance Threats” that talked of “nightmare bacteria” which “post a catastrophic threat.”

Each year in the U.S., the report said, 2 million people get “serious infections” involving drug-resistant bacteria and “at least 23,000 die” as a result.

Twenty-three thousand people is the population of Hudson. Image if every man, woman and child in Hudson died this year, and we could have stopped it.

As I say, we’re being stupid. Even poop jokes can’t hide that fact.

GraniteGeek appears Mondays in The Telegraph. David Brooks can be reached at 594-6531 or dbrooks@nashuatelegraph.com. Also, follow Brooks on Twitter (@granitegeek).